15 replies to this topic

[sgallegly]

Hi all,

Just rebuilt my 66 cooper s - crank 20 over, omega forged pistons 40 over, sw10 cam, specialist components fuel injection, 7 port aluminum head. New oil pump, center oil
Pick up and magnetic oil catch at the back of the gear case.

Before starting, pulled plugs, turned motor with just starter and got 60 lbs oil pressure. Ran in the camshaft with break in 20-50 oil at 2500
Rpm for 20 minutes. Water temp didn’t get above 185F. Then took the car for a short drive (1 mile) - I noticed the oil pressure didn’t go above 45 lbs at 3000 to 4000 rpm.

Drained the oil, changed the filter and put 20-50 fresh oil. Checked the oil pressure relief valve - all okay. Fired it up and still no change - oil
Pressure still not above 45 lbs.

Took out the gauge - no contaminants. Turned the motor over with the gauge out - spurted the oil into
A rag to clear any contaminants. Still, no change in the oil pressure.

I know the crank bearings are suited well to the crank.

The oil seal and rubber o ring were not forgotten.

Engine runs great, sounds great.

I’ve looked inside the relief valve chamber and all looks clean and clear.

I welcome any input.

Cheers,

Shawn

[Spider]

Was the Relief Valve Seat removed for cleaning and was it re-fitted ?

It could be the relief valve cracking pressure is too low. Is the Relief Valve Spring new ? If so, Try adding a washer under the cap to put more pressure on the spring. Don't go crazy here, just put one in to start with and then if need be, add another, little bit by little bit.

Just a further thought, the spring wasn't shortened at some point in time for a ball bearing was it ?

[PoolGuy]

Sorry I can’t add anything to Spiders comments, but I’m interested in the build, maybe in another thread so this one doesn’t get derailed? Cheers, and good luck.

[Lplus]

Hi all,

Just rebuilt my 66 cooper s - crank 20 over, omega forged pistons 40 over, sw10 cam, specialist components fuel injection, 7 port aluminum head. New oil pump, center oil
Pick up and magnetic oil catch at the back of the gear case.

Before starting, pulled plugs, turned motor with just starter and got 60 lbs oil pressure. Ran in the camshaft with break in 20-50 oil at 2500
Rpm for 20 minutes. Water temp didn’t get above 185F. Then took the car for a short drive (1 mile) - I noticed the oil pressure didn’t go above 45 lbs at 3000 to 4000 rpm.

Drained the oil, changed the filter and put 20-50 fresh oil. Checked the oil pressure relief valve - all okay. Fired it up and still no change - oil
Pressure still not above 45 lbs.

Took out the gauge - no contaminants. Turned the motor over with the gauge out - spurted the oil into
A rag to clear any contaminants. Still, no change in the oil pressure.

I know the crank bearings are suited well to the crank.

The oil seal and rubber o ring were not forgotten.

Engine runs great, sounds great.

I’ve looked inside the relief valve chamber and all looks clean and clear.

I welcome any input.

Cheers,

Shawn

What is the pressure at idle cold and hot?  Does the pressure reach 45psi by say 1500 rpm then stay there as the revs rise?  What is the pressure at 3000 rpm cold?  For a cooper S with the standard cooper s ball type blowoff valve and cooper S spring I'd expect at least 75 - 80 psi cold at 3000 rpm and possibly more - at least that's what I got when I fitted one to my 1275 A+ ( I changed back to the normal type.)

[Quinlan minor]

I'd be tempted to try another gauge, just in case.

[sgallegly]

Was the Relief Valve Seat removed for cleaning and was it re-fitted ?

It could be the relief valve cracking pressure is too low. Is the Relief Valve Spring new ? If so, Try adding a washer under the cap to put more pressure on the spring. Don't go crazy here, just put one in to start with and then if need be, add another, little bit by little bit.

Just a further thought, the spring wasn't shortened at some point in time for a ball bearing was it ?

Hey Spider,

 

Many thanks.  Unfortunately, my machinist didn't remove the relief valve seat (I know, groans from the crowd).  The relief valve spring is the original, so I have ordered a new Cooper s spring and new shuttle (even though it looks fine).  I have the adjustable oil pressure relief valve kit installed.  No, the spring wasn't reduced, and didn't run with a ballbearing.

 

What I find strange is that at cold before firing it up, I got 60 lbs.  When I start it at cold, the pressure doesn't go above 45lbs, and after a bit of running at 1000 rpm it sits at 25lbs, which is fine, but I am concerned the pressure will not go above 45lbs at 185F temperature at 3000 to 4000 rpm.  I've not given it the beans as it's still fresh.  

 

Replacing the seat - is this going to involve a tear down or not?

 

Thanks for all input!

[sgallegly]

 

Hi all,

Just rebuilt my 66 cooper s - crank 20 over, omega forged pistons 40 over, sw10 cam, specialist components fuel injection, 7 port aluminum head. New oil pump, center oil
Pick up and magnetic oil catch at the back of the gear case.

Before starting, pulled plugs, turned motor with just starter and got 60 lbs oil pressure. Ran in the camshaft with break in 20-50 oil at 2500
Rpm for 20 minutes. Water temp didn’t get above 185F. Then took the car for a short drive (1 mile) - I noticed the oil pressure didn’t go above 45 lbs at 3000 to 4000 rpm.

Drained the oil, changed the filter and put 20-50 fresh oil. Checked the oil pressure relief valve - all okay. Fired it up and still no change - oil
Pressure still not above 45 lbs.

Took out the gauge - no contaminants. Turned the motor over with the gauge out - spurted the oil into
A rag to clear any contaminants. Still, no change in the oil pressure.

I know the crank bearings are suited well to the crank.

The oil seal and rubber o ring were not forgotten.

Engine runs great, sounds great.

I’ve looked inside the relief valve chamber and all looks clean and clear.

I welcome any input.

Cheers,

Shawn

What is the pressure at idle cold and hot?  Does the pressure reach 45psi by say 1500 rpm then stay there as the revs rise?  What is the pressure at 3000 rpm cold?  For a cooper S with the standard cooper s ball type blowoff valve and cooper S spring I'd expect at least 75 - 80 psi cold at 3000 rpm and possibly more - at least that's what I got when I fitted one to my 1275 A+ ( I changed back to the normal type.)

 

 

Cold the pressure at start is 45lbs.  Hot at idle it is 25lbs, which is totally fine.  The issue is at higher revs, the pressure does not go up.  3000 cold is still just 45lbs.  I've owned the car for 40 years (got it when I was 17!) and 60lbs was always my cold start up oil pressure.

[sgallegly]

I'd be tempted to try another gauge, just in case.

Agree - and intend to.  I didn't yet as the gauge is relatively new, maybe 5 years old.  But agree, this is part of the diagnosing...

[sgallegly]

Sorry I can’t add anything to Spiders comments, but I’m interested in the build, maybe in another thread so this one doesn’t get derailed? Cheers, and good luck.

Happy to do so... once I figure it out!!  I've owned my 66 Cooper s since 1984 - a California import, and it's been rebuilt 3 times, this time with fuel injection (got so tired of adjusting points!).

[Cooperman]

It may well be the relief valve plunger has a small piece of swarf.
Remove the plunger and blow out the seating with a high pressure air line. Fit a new plunger and a correct ‘S’ spring with a washer under it in the closing cap.
Let us know how you get on.
What oil pump did you use. Personally I always use the Metro Turbo solid face pump having had some issues with the current spec ‘standard’ ones.
Your engine spec sounds great.

[sgallegly]

It may well be the relief valve plunger has a small piece of swarf.
Remove the plunger and blow out the seating with a high pressure air line. Fit a new plunger and a correct ‘S’ spring with a washer under it in the closing cap.
Let us know how you get on.
What oil pump did you use. Personally I always use the Metro Turbo solid face pump having had some issues with the current spec ‘standard’ ones.
Your engine spec sounds great.

Hi Cooperman, thank you for your input.  Good call on blowing the seat out. I'm wondering if the swarf might come from the fresh engine's engagement with the  "run-in" motor oil - maybe created some extra junk in the oil line, which is why I drained it after the 20 minutes of run in and changed the filter.  

 

Regarding the oil pump, I have a new one from MED.

 

Once again, I sincerely appreciate your and all others input!  I'll keep you all updated!

 

Cheers,

 

Shawn

[Spider]

Hey Spider,

 

Many thanks.  Unfortunately, my machinist didn't remove the relief valve seat (I know, groans from the crowd).  The relief valve spring is the original, so I have ordered a new Cooper s spring and new shuttle (even though it looks fine).  I have the adjustable oil pressure relief valve kit installed.  No, the spring wasn't reduced, and didn't run with a ballbearing.

 

What I find strange is that at cold before firing it up, I got 60 lbs.  When I start it at cold, the pressure doesn't go above 45lbs, and after a bit of running at 1000 rpm it sits at 25lbs, which is fine, but I am concerned the pressure will not go above 45lbs at 185F temperature at 3000 to 4000 rpm.  I've not given it the beans as it's still fresh.  

 

Replacing the seat - is this going to involve a tear down or not?

 

Thanks for all input!

 

 

Ah, OK, an adjustable valve.

Try winding it up some, just little by little. These set the maximum pressure.

 

If it has the seat in there now, don't worry about removing it at this point.

 

to be honest here, even at 45 PSI, that's nothing I'd worry too much about, that's well enough oil pressure for these engines on modern oil. The MPi only ran 30 PSI.
 

[sgallegly]

 

Hey Spider,

 

Many thanks.  Unfortunately, my machinist didn't remove the relief valve seat (I know, groans from the crowd).  The relief valve spring is the original, so I have ordered a new Cooper s spring and new shuttle (even though it looks fine).  I have the adjustable oil pressure relief valve kit installed.  No, the spring wasn't reduced, and didn't run with a ballbearing.

 

What I find strange is that at cold before firing it up, I got 60 lbs.  When I start it at cold, the pressure doesn't go above 45lbs, and after a bit of running at 1000 rpm it sits at 25lbs, which is fine, but I am concerned the pressure will not go above 45lbs at 185F temperature at 3000 to 4000 rpm.  I've not given it the beans as it's still fresh.  

 

Replacing the seat - is this going to involve a tear down or not?

 

Thanks for all input!

 

 

Ah, OK, an adjustable valve.

Try winding it up some, just little by little. These set the maximum pressure.

 

If it has the seat in there now, don't worry about removing it at this point.

 

to be honest here, even at 45 PSI, that's nothing I'd worry too much about, that's well enough oil pressure for these engines on modern oil. The MPi only ran 30 PSI.
 

 

Thanks for the feedback.  I get it, but it bothers me as the oil should be higher, especially for a Cooper s 1275... I don't want to mess it up!  

 

I'll keep you all posted!

 

Cheers!

 

Shawn

[Spider]

Thanks for the feedback.  I get it, but it bothers me as the oil should be higher, especially for a Cooper s 1275... I don't want to mess it up!  

 

I'll keep you all posted!

 

Cheers!

 

Shawn

 

Sure, see how you go with adjusting the valve. Be mindful too, that like most things, " more is not always better " and this is true of Oil Pressure.
 

[sgallegly]

Everything in moderation! 😉